Middle School Chemistry Physics questions

r1 = 24 ohms r2 = 9 ohms.

If connected in parallel, the actual power of the lamp must not exceed its rated power, then the voltage at both ends is 6V, at this time P1=6 2 24 W= P2=6W So P Total =

If it is connected in series, the rated current of lamp 1 is 6 12 A = lamp 2 current 4 6 A = 2 3a, so the maximum series current is P1 = 6W P2 = 9 4w So P total = 33 4W In summary, the maximum power is 33 4W

This problem is the easiest to use conservation, and the magnesium element ultimately exists in the form of magnesium sulfate, so the final mass of magnesium sulfate: 10*48% [24 (24+96)] g=24g

24 (24+96)] is the mass fraction of magnesium element in magnesium sulfate.

Because r=uu p so r1=24 ohms r2=9 ohms.

If it is connected in parallel, the actual power of the lamp shall not exceed its rated power, then the voltage at both ends is 6V, at this time P1=6*6 24 = P2=6W So P Total =

If it is connected in series, the rated current of lamp 1 i = 6 12 = lamp 2 current i = 4 6 = so the maximum series current is p1 = 6w p2 = so p total = in summary, the maximum power.

Magnesium eventually exists in the form of magnesium sulfate, so the final mass of magnesium sulfate: 10*48% [24 (24+96)] g=24g

24 (24+96)] is the mass fraction of magnesium element in magnesium sulfate.

mg(oh)2+h2so4=mgso4+2h20mgo+h2so4=mgso4+h20

24/240=x/54

x=solution mass=

The first question is two resistors, one is 12v24 ohms, the other is 6v9 ohms, if they are connected in parallel, the maximum added circuit voltage can only be 12v, and the total power consumed is 12*12 (72 11)=22w, if it is connected in series, the maximum current that can be added can only be Considering the range of the circuit voltage, within the range, the power at this time is ( The maximum value is 22W

Question 2 The right amount of dilute sulfuric acid is not given so it can't be calculated.

1. First find the resistance of the two lamps, respectively 36 ohms and 9 ohms, the rated current of the two lamps is 1 2 and 2 3, because the two lamps are connected in series, to take the small current as the standard, so that the current in the circuit is 1 2, and then calculate the power of the two lamps according to i 0 5r, and the maximum value can be obtained by adding (1 2) 0 5 36 (1 2) 0 5 9 9 9 4

1 p=u2 r The resistance should be reduced The actual power of the parallel lamp must not exceed its rated power.

u total = 18v p = 10w

The answer is a bit more concise).

2 I haven't studied chemistry yet

The second floor is correct, but it needs to be added.

The mass of the solution should also be added with water, mg(oh)2+h2so4=mgso4+2h20

mgo+h2so4=mgso4+h20

24/240=x/54

x=solution mass=

1) In the above chemical reaction equation, the chemical formula of the corresponding product in " " is H2O.

2) The valency of copper before and after the chemical reaction changes from +2 valence to 0 valence.

3) The mass fraction of carbon in methane is 12 16*100%=75%.

1.All the coefficients tell you, H4O2 is divided again, and the first empty H2O

2.Copper oxide is positive 2, so from +2 to 0